The aim of this project is to identify the relative role of various lymphocyte populations in disease production in experimental allergic encephalomyelitis, a model of autoimmune disease. These studies will focus on the ability to transfer EAE with various populations of lymphocytes particularly T and B cell populations. In addition, the in vitro response of these cell populations to myelin basic protein will be examined. The relationship of the host genetic makeup to disease susceptibiliy will also be examined both in vitro and in vivo. The in vitro studies will consist of T cell recognition and resonsiveness to basic protein. In vivo studies will include studies of the differences in disease production in various strains of both mice and rats.